In recent years, as described in Patent document 1 (JP-A-2005-315202), there has been a vehicle mounted with an engine automatic stop-start system (idle stop system) that performs control for increasing a target current value of an alternator to an initial value set at a large value beforehand and then decreasing the target current value when an engine is stopped automatically, aiming to control an engine rotation stop position (stop crank angle) into a crank angle range, which is suitable for start, during engine stop (idle stop) and to improve restarting performance.